Graded Index Multi Mode Fiber

The advantage of the multi mode graded index compared to the multi mode step index is the considerable decrease in modal dispersion.

Graded index multi mode fiber.

The light wave that travels inside the fiber changes its behaviour with time while travelling inside it. Graded index multimode optical fibers optimized for signal transmission at 850 and 1300 nm are available with 50 125 62 5 125 and 100 140 µm core cladding diameters. The large diameter of the core allows multiple rays to propagate through the fiber. Thus 62 5 125 μm multi mode fiber has a core size of 62 5 micrometres μm and a cladding diameter of 125 μm.

Suitable for light wave communication links and local area networks carrying voice video and data standard and high temperature up to 375 c versions. Graded index fiber is a type of fiber where the refractive index of the core is uniform at the center core and then it decreases towards core cladding interface. The diameter of core in graded index multimode fiber is somewhat between 50 to 100 micrometer. Modal dispersion can be further decreased by selecting a smaller core size less than 5 10μm and forming a single mode step index fiber.

The transition between the core and cladding can be sharp which is called a step index profile or a gradual transition which is called a graded index profile. Because of the larger core size compared to single mode fiber these fibers provide a higher transmission capacity and are used for short range communication networks and high speed transmission applications. Multi mode fibers are described by their core and cladding diameters. High temperature coatings for 150 c and 300 c.

Graded index multimode fiber. 50μm and 62 5μm variants. Graded index fiber is of only one type that is multi mode fiber. Index profiles is in the shape of a parabolic curve for α 2.

This type of fiber is normalized by the international telecommunications union itu t at recommendation g 651 1.